- fixed: Hexen's poison cloud needs to call P_DamageMobj, even with a damage value of 0. Added a new flag to handle this case because normally this is not desirable.

src/actor.h

@@ -387,6 +387,7 @@ enum ActorFlag7
 	MF7_SPRITEANGLE		= 0x02000000,	// [MC] Utilize the SpriteAngle property and lock the rotation to the degrees specified.
 	MF7_SMASHABLE		= 0x04000000,	// dies if hitting the floor.
 	MF7_NOSHIELDREFLECT = 0x08000000,	// will not be reflected by shields.
+	MF7_FORCEZERORADIUSDMG = 0x10000000,	// passes zero radius damage on to P_DamageMobj, this is necessary in some cases where DoSpecialDamage gets overrideen.
 };
 
 // --- mobj.renderflags ---

src/p_map.cpp

@@ -5674,8 +5674,9 @@ int P_RadiusAttack(AActor *bombspot, AActor *bombsource, int bombdamage, int bom
 			}
 			points *= thing->GetClass()->RDFactor;
 
+			double check = int(points) * bombdamage;
 			// points and bombdamage should be the same sign (the double cast of 'points' is needed to prevent overflows and incorrect values slipping through.)
-			if ((((double)int(points) * bombdamage) > 0) && P_CheckSight(thing, bombspot, SF_IGNOREVISIBILITY | SF_IGNOREWATERBOUNDARY))
+			if ((check > 0 || (check == 0 && bombspot->flags7 & MF7_FORCEZERORADIUSDMG)) && P_CheckSight(thing, bombspot, SF_IGNOREVISIBILITY | SF_IGNOREWATERBOUNDARY))
 			{ // OK to damage; target is in direct path
 				double vz;
 				double thrust;
@@ -5752,7 +5753,7 @@ int P_RadiusAttack(AActor *bombspot, AActor *bombsource, int bombdamage, int bom
 
 				double factor = splashfactor * thing->GetClass()->RDFactor;
 				damage = int(damage * factor);
-				if (damage > 0)
+				if (damage > 0 || (bombspot->flags7 & MF7_FORCEZERORADIUSDMG))
 				{
 					//[MC] Don't count actors saved by buddha if already at 1 health.
 					int prehealth = thing->health;

src/scripting/thingdef_data.cpp

@@ -316,6 +316,7 @@ static FFlagDef ActorFlagDefs[]=
 	DEFINE_FLAG(MF7, SPRITEANGLE, AActor, flags7),
 	DEFINE_FLAG(MF7, SMASHABLE, AActor, flags7),
 	DEFINE_FLAG(MF7, NOSHIELDREFLECT, AActor, flags7),
+	DEFINE_FLAG(MF7, FORCEZERORADIUSDMG, AActor, flags7),
 
 	// Effect flags
 	DEFINE_FLAG(FX, VISIBILITYPULSE, AActor, effects),

wadsrc/static/zscript/hexen/flechette.txt

@@ -437,7 +437,7 @@ class PoisonCloud : Actor
 		Mass 0x7fffffff;
 		+NOBLOCKMAP +NOGRAVITY +DROPOFF
 		+NODAMAGETHRUST
-		+DONTSPLASH +FOILINVUL +CANBLAST +BLOODLESSIMPACT +BLOCKEDBYSOLIDACTORS
+		+DONTSPLASH +FOILINVUL +CANBLAST +BLOODLESSIMPACT +BLOCKEDBYSOLIDACTORS +FORCEZERORADIUSDMG
 		RenderStyle "Translucent";
 		Alpha 0.6;
 		DeathSound "PoisonShroomDeath";